Optical device for radio cinematographic transmitters and receivers



Nov. 4, 1930. L. THURM 7 OPTICAL DEVICE FOR RADIO CINEMATOGRAPHIC TRANSMITTERS AND RECEIVERS Filed July 14, 1928 3 SheetsSheet 1 BIG. 1

iElGi L. THURM Nov. 4, 1930.

OPTICAL DEVICE FOR RADIO CINEMATOGRAPHIC TRANSMITTERS AND RECEIVERS Filed July 14-, 1928 5 Sheets-Sheet 2 I l/l/VE/VTOR. Leon T/Lza'm.

Patented Nov. 4', 1930 UNITED. STATES PATEN }orrics LEON THUBM, orremsrnenon r OPTICAL DEVICE'FOR RADIO CINEMATOGRAPHIC. Assamese man anese;

Application filed July 14,1928, Serial No; 292,311, anaemi J'i 11y21, 1927.

- The present invention relates to an optical ters and receivers.

v device for radio-cinematographic transmit The view-taking apparatus adapted to form the imagesupon the film maybe of, the known type, butl preferably employ a simplified' apparatus in which the'ifilm. travelscontinuously and at a constant speed. In front of the filmlis moved, atthe properspeed and at to right angles to the'direction of travel of the film, a shutter which may consist of aflexible band, a disk or the like comprising slots parallelwith the film to; be printed upon.

Aftr the printing of the images,the film travels infront of afshutter placed behind the flens adaptedto refract a beam froman iljugated image plane of the object plane containing the illuminant in the rear of a fixed screen, suitably: apertured. In front of said screenis rotatable a disk, havingseries' of slots disposedupon two semicircles; and the length of one slot.

two series are relatively displaced by the is equal to one-half the 'surface of opening of the screen. At the rear of. the film is placed a photo-electric bulb or a group of suchbulbs which serve to modulate the transmitted waves of a radio transmitting station.

Such transmitted waves are'recorded in the receiving stationbyn elements of an electromagnetic device described in the French February 5th, 1927 andforming the subject 'matter of my U.- S. application, Serial No;

248,924, filed January 23rd,.1928. These" 07..

elements vary each of the. currentsfiowi'ng in the n circuits, each circuit comprising an il.-',

luminant whose light depends upon the variations of the currents in the n circuits.

These illuminants, which may consist of a set of neon bulbs, are; placedin a shutter cylinder, and the rays which pass through it" are reflected upon a lens by'a drum compris- The surface ofsaid slots ascreen. patent granted to me under No. 640,115 of of parallelograms. f

Behind thesei 'bulbG.

"Theshu'tter at comprises two series of aper- .The appen ed drawings ShOW byway of example an embodiment'of the invention Fig.1 is a partial front viewoftheshutter movable: inv front 0f the film at angles electric bulb upon Which fall the lightbe ams straining through the film.

Fig.4 is a front view of the. shutter disk Fig. 5shows the parts of the film-which "are alternately covered in an intermittent luminantof suitable powcr, supplied byaf manner by the light from the illuminant. I 'Fig. 6 shows a modification of theoptical plane which contains the illuminant, the

film 'being'situatedi' with reference to the other lens in the conjugated planefof'the vplane'which contains'the closing device.

. ig. 7 shows theshutter cylinder contain-v ing the neon or other bulbs.

Fig. 8 is apartial view of the cylinder 7 when opened out, showing its full and empty parts.

Fig. 9' shows the optical 'devi'ce placed i the receiver for the reproduction ofthe consecutive images of'the transmitted; film upon ljis'the shutter which comprises the slots 1 suitably spaceda art and which moves at a given speed in rontof the film 2 and at right angles to its direction of travel. Due to thecombined. motion of the shutter land the film 2, this latter is printed with the; images at the parts2 having the form In Fig. 3, which shows the optical sys- 'tem, 3 is the lens in relation to which the rotating shutter disk 4, the screen 5.and the film 2 are placed intheconjugated plane of the plane which contains the illuminant. s situated the photo-electric tives occupy In Fig. 6, 8 is the condenser adapted to condense the beam upon the shutter, and said beam then passes through the lens 3 by which they are converged-through the film 2- upon the photo-electric bulb 6 which com= prises in its circuit the amplifier 9.

At the receiving end, a series of neon bulbs 10 is placed in a shutter cylinder 11, comprising empty or filled parts 11*, 11, perpendicular to the axis of the cylinder.

The optical device shown in Fig. 9 comprises a. drum 12v carrying the mirrors 12, also the lens 13 and screen 14.

The operation is as follows:

The views-taking apparatus may be an apparatus which operates in the following manner. The film 2, instead of traveling by jerks, travels by a continuous and uniform motion. The shutter 1 moves at right angles to same plane, and may have the same size and shape as the film. The said shutter is opaque upon its whole surface except upon the small and very narrow rectangles l Whichare spaced apart at equal distances in the direction of the width of the shutter. While the film 2 moves upwardly, the said shutter Will move for example from right to left. The which is supposed to be properly placed in a view-taking apparatus, may thus take the images, not according to rectangular images as in the usual film, but according. to parallelograins 2 disposed without intervals the one below the others.

Let it be supposed that a film thus carrying images is employed, and that its negastance 24: mm. height and width. I place this film before a lantern apparatus in the plane in which there is formed a real image of the illuminant placed on the other side of the lens. Between the lens and the film, and adjacent the film, I place a shutter consisting of a perforated disk 4 and a fixed screen 5 having the rectangular aperture 5 in such manner that if the rotary disk 4 werenot in place, a rectangular spot of light would be 7 formed upon the film 2. TallGdISk may carry two sets of holes which may be square, and

these are so placed that by the motion of the disk there will be disengaged one half of the rectangular aperture 5 of the screen 5; if for instance the disk 4 has 200 apertures, each half of the aperture 5 of the screen 5 will be. closed 100 times during a revolution of the disk. If when the disk is rotating, the

of the said the travel of the film 2 and in the v parall'elograms having for -in-.

film 2 moves in the direction of the arrow in Fig. 2, two parts 7-7 (Fig. 5) of the film 2 will be alternately covered in an intermittent manner by the beam of light. I may obtain like results by placing the shutter between the condenser 8 and the lens 3 in the image plane of the illuminant relatively to the said condenser (Fig. 6).

If for instance 20 images, 2 1 mm. height and width, travel in one second before the lens, and if the disk 4 carrying two series of 100 apertures a -4r" makes-lOjrotations per second, while the screen 5 has an aperture 5* such that each time that anaperture in the disk passes, it would illuminate a square of 0.3 mm.eof the film 2 if the filmwere stationary, the rotating device will alternately scan, each tenth of a second, a space T and a space 7 (Fig.5). N

After the first passage of the film 2, it may be moved in such manner that the spaces 7 and 7 will be covered in the same manner when the film passes a second time.

the transmitted waves of a radio stationwhich Would have been recorded. at the receiving station on the 4:0 elements'of a known electromagnetic device such as that described in the French patent granted to me under N0. ($0,115 of February 5th, 1927 and forming the subject matter of my U. application, Serial Number 2%,924 filed January 23rd, 1928, each ele'rnent consisting essentiallylin an electro-magnet, recording current variations upon a magnetic spiral.

v In this manner I am enabled to reproduce at the receiving station the scene which was recorded on the film at the transmitting station. For this purpose, I place in each of the 40 circuits modulated by the 4:0 elements of placed in the interior of a shutter. cylinder,

parallel with the axis but quite near the lateral surface, as shown in Fig. 7 which is a section perpendicular to the axis of the cylinder, and if I rotate the shutter cylinder 11 whose lateralsurface, when spread out, has the appearance shown in Fig. 8, one-half of each luminous spot will be alternately shut off by the solid part of the shutter 11 if these parts, and hence the apertures, have a width equal to one-half thelength of each luminous spot. Hence, if the shutter 11 comprises 80 the whole making for instance two revolutions per from the spirit also suitably modify the'details of the disk shutter may and the size and shape I the disk may vary inorder to increase the efliciency.

second, has a circumference of one meter,

each half of each luminous spot will be visible and darkened alternately each 1/20 second.

Opposite this arrangement I may place a. drum carrying 10 planemirrors and making two revolutions persecond; an observer at 13 would then see at,.15 the moving image of the scene recorded on the film at the trans mitting station. "Ifin the place of the observer I dispose a lens, the said film-recorded scene may be reproduced upon ascreen placed at 14 (Fig.9),

' Obviously, I may employ otherconstructional forms ofapparatus without'departing of the invention, and may construction and assembling. For the aforesaid parts described by Way of example, I may substitute other partsserving the'samepurpose and affording likeresults. Y I r In this manner, inthentransmitting station be replaced by a cylindrical shutter. In the receiving station, the closing drum may be replaced by a disk.

It is furtherobvious that the number of neon or other bulbs maybe varied, asalso the number'of apertures or seriesof spots of the closing system. A

The number of series of apertures in the shutter disk o fthe sending station may vary according to the speedof rotation of said disk, of the apertures, in

' The film at the transmitting station may be a positive or a negative film, and in this latter case, it will be simply necessary to of said film, equal to a certain different circumferences,

istering with each of said series of openings in the shutter upon rotation thereof for alternately exploringtwo longitudinal regions predetermined portion' of the width of said film.

7 3. A device of the character described comprising a film, a rotatable shutterhaving two each region having a length I opposed semi-circularseries of openingsof g a screen disposed between the shutter and the film and carrying a rectangular aperture capable of successively registering with of openings in the shutter upon rotation thereof, and a photoelectric bulb disposed to receive a beam of light passing through the shutter and film for modulating the longitu= dinalregions of the film explored by said shutter and screen.

4. In a device of the character described, a uniformly traveling film, a shutter having a ertures formed therein, said shutter movin eachof said series plurality of rectangular and equi-distantapuniformly in a plane parallel to that of the film but in a direction perpendicular to the travel of said film, whereby the views formedon the film by the light passing through the rectangular andequi-distant apertures of the shutterwill be juxtaposed and have the form of parallelograms.

' nwitness whereof have hereunto set my a LEON THURM.

hand.

reverse the variations of the currents in the 7 amplifying system.

The time of the transmission may be much reduced by the use of a multiplex outfit,'so I arranged for instance that several beams of light 1' will. simultaneously cover. different spots o'fthe film, thus'modulating one or of photo-electric bulbs.

l. A device of the character described comprising a film, a rotatableshutter having series of openings formed therein, said openings displaced in position with rotation of the shutter, a screen disposed between the shutter and the film andcarrying a rectangular aperture of a length equal to the double ,more waves bymeans of a certain number 1 

